man: add note regarding editing user groups

Currently the manual doesn't clearly say whether `homectl update username -G group` will append the group to the user, or overwrite the list and remove user from the groups that aren't specified.

Fix this by updating the manual, basing the change on the usermod manual.

man/homectl.xml

@@ -268,7 +268,8 @@
         independently, for example with <citerefentry
         project='man-pages'><refentrytitle>groupadd</refentrytitle><manvolnum>8</manvolnum></citerefentry>. If
         non-existent groups that are listed there are ignored. This option may be used more than once, in
-        which case all specified group lists are combined.</para></listitem>
+        which case all specified group lists are combined. If the user is currently a member of a group
+        which is not listed, the user will be removed from the group.</para></listitem>
       </varlistentry>
 
       <varlistentry>

man/systemd-modules-load.service.xml

@@ -29,14 +29,15 @@
   <refsect1>
     <title>Description</title>
 
-    <para><filename>systemd-modules-load.service</filename> is an
-    early boot service that loads kernel modules based on static
-    configuration.</para>
+    <para><filename>systemd-modules-load.service</filename> is an early boot service that loads kernel
+    modules. It reads static configuration from files in <filename>/usr</filename> and
+    <filename>/etc</filename>, but also runtime configuration from <filename>/run</filename> and the kernel
+    command line (see below).</para>
 
     <para>See
-    <citerefentry><refentrytitle>modules-load.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
-    for information about the configuration of this service.</para>
-
+    <citerefentry><refentrytitle>modules-load.d</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
+    information about the configuration format of this service and paths where configuration files can be
+    created.</para>
   </refsect1>
 
   <refsect1>

src/network/networkd-dhcp-server.c

@@ -116,7 +116,7 @@ static int link_push_uplink_to_dhcp_server(
         case SD_DHCP_LEASE_LPR:
                 /* For the other server types we currently do not allow local configuration of server data,
                  * since there are typically no local consumers of the data. */
-                ;
+                break;
 
         default:
                 assert_not_reached("Unexpected server type");